Saturday, February 27, 2010

Tsunami no-show, Minnesota quakes, risk of a real storm?

Potential for an actual "storm"? You remember storms, don't you? The inevitable "watches" and "warnings"? The frantic drive to Cub to stock up on food and water? The non-stop meteorological hype on area radio and TV stations, begging you not to go outside? I have fond memories (of something to point to on my vacant weather map). The GFS model is hinting at a "plowable" snow around March 9-10. My confidence level? Low. It's way out on the horizon; much can and will change as the weather evolves and new data arrives (we get 4 new computer runs every day - in theory each successive model run should get closer to reality). We'll keep you posted. Stating the obvious: we're due.

Remember back when we could build jumbo-snowmen? I don't either. I vaguely remember the Halloween Blizzard, yes '91-92 was a rough winter. So was '96-97. Since then snow has been the exception, not the rule. Now we get excited over a lousy inch or two. For a list of Minnesota's toughest winters from the MN State Climatology Office click here.

Dirty Snow. Snowfall amounts drop off the farther north/west you travel across the state. 11" on the ground in St. Cloud and Brainerd - far more near Lake Superior: 24" at Duluth, close to 30" near Grand Marais. To get the latest snow amounts check out for all the details.

Minnesota: a mostly-earthquake-free zone. Geologically speaking Minnesota's faults are old, ancient really, dating back hundreds of millions of years. Relatively speaking the ground under our feet is firm and stable. We have felt minor tremors in the past, during the 60s and 70s quakes centered in Illinois were felt in the Twin Cities. Note the earthquake bulls-eye over the middle Mississippi River Valley - the "New Madrid Fault" is capable of severe tremors, impacting major cities from St. Louis to Memphis and Nashville, not traditionally thought to be in "earthquake alley." In 1811-1812 a major quake temporarily reversed the direction of the Mississippi River, ringing church bells as far away as Boston. For more on the New Madrid fault click here.
Minnesota tremors. On July 9, 1975 a 4.6 quake shook towns near Morris, MN, resulting in minor damage to walls and foundations. Another quake centered in southern Illinois on November 9, 1968 was felt in the Twin Cities metro area. More historical information on Minnesota quakes from the USGS is here. That said, the probability of a moderate or major earthquake in Minnesota is thought to be negligible. Cold comfort indeed.

File photo of a tsunami. Actually, the more I stare at this image the more I believe it may have been Photoshopped. There are SO many weather-related photos floating around on the 'net that have been heavily retouched, doctored, tampered with. It's getting harder and harder to discover what is real, and what is an altered version of reality. Although tsunamis are one of the few natural disasters Minnesotans don't have to worry about - some day you may be visiting/vacationing in a spot that is vulnerable. If you're near the ocean and there's a major quake within a few thousand miles you'll need to get to higher ground, or evacuate vertically (meaning at least the third story of a well-constructed building or hotel). For more information on how to survive a tsunami click here. Data courtesy of the USGS. Travel into earthquake country? I'm talking L.A., San Francisco, Seattle (as well as Memphis and St. Louis?) Check out these suggestions on how to survive an earthquake.

And here I thought meteorology was an inexact science. I realize authorities HAD to err on the side of safety and precaution, but it really did turn into quite the media spectacle this afternoon, waiting for the anticipated tsunami to engulf Hawaii. Webcams deployed, scores of reporters Skyping and Tweeting and just generally trying to fill time, waiting for the Big One to arrive. Don't get me wrong, I'm as relieved as everyone else that the predicted tsunami was a dud, after witnessing the carnage and incredible violence of what an 8.8 magnitude earthquake did to Chile. Our hearts & prayers go out to the people of Chile - I don't think any of us can imagine the heartache and agony taking place right now in that culturally-rich nation. No power for much of the nation. No clean water or sanitation. The unearthly silence interrupted by random screams of those still trapped in the wreckage. The quake was an estimated 500 times more intense than what Haiti endured weeks ago - the only upside: most of the homes and office buildings were newer, built under more stringent building codes - many of them remained upright, in spite of the severe shaking. Survivors report seeing "waves" rolling along the ground, the normally firm soil underfoot turning to jelly. I can't even wrap my brain around that one...

Ground Zero. Saturday morning's 8.8 quake may have been as much as 500 times stronger than the major tremor that struck Haiti a few weeks ago. If you're feeling especially paranoid feel free to sign up for (free) tsunami alerts from NOAA by clicking here.

The truth? Much like meteorology, where every day is unique and every storm is different - every earthquake has different dynamics. In the case of the Chilean quake my only thought is that much of the energy from the tectonic plates grinding past each other in a sudden, agonizing - unimaginable tremor lasting 2-3 minutes. A major quake pushes the sea floor up and down violently, resulting in a series of massive waves emanating from ground zero of the tremor. If the quake is out at sea, ALL the energy is dissipated outward in the form of tsunami waves. But if you were on a boat in the middle of the ocean you wouldn't even notice - seas would rise and fall about 1 foot, give or take, as a 90 mile long surge of water races undernearth you at close to 500 mph. But as you approach land and the sea surface turns sharply upward toward land, the water "piles up", accumulates, coming ashore not as a single, monster-wave, but as a series of rapidly building surges that spill ashore, each wave of water a liquid-battering ram, each successive surge of water larger than the last.

Vulnerable to Tsunamis. Here are the locations of the world's most devastating tsunamis (nearly 2000 major events from 1628 BC to 2004). Click here to go directly to the Tsunami Laboratory to learn more. A mind-numbing list of tsunami links are here. No, I have no life.

Everyone feared a rerun of the Indonesian earthquake and super-tsunami of December 26, 2004, which was estimated to be between a 9.1 and 9.3 quake, lasting an unimaginable 8-10 minutes, causing the entire planet to "vibrate" by as much as 1 cm. (Wikipedia). The resulting tsunami killed nearly a quarter million residents of Indonesia, India and Thailand, waves as high as 100 feet breaking against the coast, wiping out hundreds of coastal towns. Thankfully today's quake (although in the same league) was not as severe as the 2004 tremor - and much of the energy may have been dissipated over land, (bad news for Chile) but ultimately sparing a destructive tidal wave that would have impacted some or all of the 53 nations ringing the Pacific Ocean.

I am not a seismologist, and I don't play one on TV. I'm amazed how many TV-meteorologists-by-day were thrust into the limelight today, expected to narrate the quake and tsunami details, the science behind the phenomena. All in all I thought they did an admirable job, under difficult circumstances. It proves my theory that all these local meteorologists are the staff scientists, expected to interpret any and all scientific data, whether it's earthquake aftermath, volcanoes, or climate science. I tell any kids who will listen (my own tuned me out years ago) that they will never, ever be done learning, and to soak up new information (and new hardware/software tools) whenever and wherever possible, because you just never know when you might be called on to speak extemporaneously about an 8.8 magnitude earthquake.

Like something out of a Norman Rockwell painting? Residents of New York may have other, less family-friendly words to describe what they just endured. 17" at Central Park (37" for the month of February, an all-time record for any month). As much as 34" of snow (without the drifts) fell just 60 miles outside of New York. A cool 1-3 feet of snow blanketed much of New England, the result of the storm stalling, doing a big 48+ hour loop almost directly above New York City. Hundreds of thousands of residents are still without power. For a summary from the New York Times click here.

Obligatory cute puppy shot. Check out those hot-purple booties! You have to try and keep your sense of humor, right?

Paul's Conservation MN Outlook for the Twin Cities and all of Minnesota

Today: More sunshine, drippy by afternoon. Winds: NW 5-10. High: 33

Sunday night: Increasing clouds. Low: 12

Monday: Patchy clouds, few passing flurries possible (from the remnants of the New England storm). High: 30

Tuesday: Plenty of sun, a bit cooler. High: 32

Wednesday: Blue sky, thawing out. Low: 13. High: 33

Thursday: Partly sunny, still quiet and dry. Low: 17. High: 34

Friday: Cloudy, a little light snow/rain possible. Low: 21. High: 36

Saturday: Mostly cloudy, few flurries/drizzle possible. Low: 23. High: 37

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